Induction of apoptosis by 2,3-dehydrosilybin via a caspase-dependent pathway in human HeLa cells

Abstract

The aim of this study was to investigate the mechanisms involved in the apoptosis of HeLa cells due to 2,3-dehydrosilybin (DHS) treatment. DHS treatment over 24 h significantly inhibited cell viability and induced apoptosis in a dose-dependent manner. It also triggered the cleavage of caspase-8, caspase-9, caspase-3, and PARP, and significantly increased caspase-3 activity in a dose-dependent manner. Moreover, it triggered the depolarization of the mitochondrial membrane potential (Δψm), the release of cytochrome c into the cytosol, the cleavage of Bid, and the downregulation of Bcl-2 in a dose-dependent manner. Furthermore, z-VAD-fmk (a pan-caspase inhibitor) and z-IETD-fmk (a specific caspase-8 inhibitor) abolished the DHS-induced activation of the caspase-8, -9, and -3, cleavage of PARP, the depolarization of Δψm, the release of cytochrome c, the cleavage of Bid, and the downregulation of Bcl-2. Taken together, these results suggest that DHS-induced apoptosis is mediated by a caspase-dependent pathway in human HeLa cells.